Vulcanizing apparatus.



W. FROST.

VULGANI ZING APPARATUS. APPLICATION FILED 1930122, 1908.

fiatented Mar. 15; 1910.

WILLIAM rnosr, or LoNnoN, ENGLAND.

VULCANIZING APPARATUS.

Specification of Letters Patent.

Patented Mar. 15, 1%)10.

Application filed December 22, 1908: Serial No. 468,766.

To all whom it may concern:-

Be it known that I, WVILLIAM F ROST, a subject of the King of England,residing at London, in England, have invented a certain new and usefulImprovement in Vulcanizing Apparatus, of which the following is aspecification, reference being had therein to the accompanying drawings,forming part thereof.

My invention relates to improvements in vulcanizing apparatus.

In vulcanizing tubes and other articles of sheet rubber, such as thetubes of pneumatic tires, it is customary to use metal molds,

which are heated by steam or otherwise and are provided with openings orcavities of suitable form to embrace closely the articles to bevulcanized so as to subject them to both heat and pressure. Where thearticles oper ated upon are in the form of endless tubes,

- as in the case of the inner or air tubes of pneumatic tires, the moldused for joining the tubes or similar articles is in the form of a ring,and provision must be made for removing the tubes transversely from themold, since they obviously cannot be removed endwise. For this purposesuch molds have been constructed, heretofore, of two members, each ofwhich comprises substantially one-half of the mold and "is provided withmeans for heating it, and the two members have been removably securedtogether by hinges and bolts so that they might be separated to permitthe removal of the tubes.

In the construction above described the movability of one of the membersinvolves,"

tion is to produce a mold consisting mainly of a single stationaryheated body and requiring no flexible steam coiuiections or joints.

In carrying out my invention, I avail myself of the flexibility of thearticles to be operated upon. Instead of dividing my mold in halves, Iuse a single body which nearly surrounds the tube or other article andwhich is heated, as a unit, by steam ad- 'mitted through stationaryconnections, or in any other convenient manner. To permit the tubes tobe inserted and removed, I make a narrow gap at one point in the body,which is suflicient to admit the tube or other hollow article when it iscollapsed. \Vhen the mold is in operation, however, this gap is closedand the inner surface of the mold is completed by a small block of metalwhich is inserted for this purpose. This block is so narrow that nospecial means are necessary for heating it, since it receives suflicientheat by conduction from the body of the mold.

The invention thus consists, broadly stated,

in making the movable member of the mold so small that it may be heatedby conduction from the fixed member, while the latter alone is providedwith steam connections or other heating means.

I will now describe the embodiment of my invention illustrated in theaccompanying drawings, and will thereafter point out my invention inclaims.

Figure l is a front elevation'of-a vulcanizing mold in condition foroperation. Fig. 2 is an end view of an expanding mandrel used inconnection with the mold of Fig. 1. Fig. 3 is a longitudinal section ofthe mandrel of Fig. l.

The mold illustrated in Fig. 1 comprises a body I of circular form,which has a cir-. cular inner surface 2 constituting the vulcanizingsurface of the mold. The mold is hollow, as indicated in dotted lines,and is heated by steam or other hot fluid admittedthrough a-pipe Themold is mounted upon a Work bench or in any convenient position by meansof a threaded stem at and a wing nut 5. A cock 6 is provided for theescape of air and water of condensation.

A narrow gap 7 is provided to admit and remove the work from the mold.When the mold is in use this gap is closed by a block 8 of metal, whichis secured in place by means of a threaded-stem 9 fixed to the block andcarrying a washer 10 and a wing nut 11. The inner face 12 of this blockis formed as a continuation of the inner surface 2 of the mold, so thatwhen the block is in place an unbroken surface is presented to the work.The block is so small that no means are necessary for heating itindependently, and it may therefore be removed and replaced very quicklyand conveniently upon loosening the wing nut 11 by an endwise movementof the block in the gap'7.

In jointing a rubber tube-it is customary to support the tube interiorlyby a split mandrel which is passed over the tube, the

"connection with it a mandrel which may be Y "more or less expanded soas 'to' subject the "fw'o'rk to pressure from'within, and I- haveillustrated a suitable mandrel for this purpose in Figs. 2 and? Thismandrel is the subject of a patent issued to Walter Henry Welcln'on June1,1909, No. 923,224, and is not specifically claimed herein.

' The mandrel comprises a body 13 of flexiblej sheet metal having a'generally cylindrical form. This body-is interrupted to providea gap forthe admission of the work.

Q To'expa'nd the mandrel one edge of the body at-the gap is providedWith a curved rack 14, while the opposite edge is secured to lugs 1 15,in which is'journaled a'shaft 16. The

shaft is provided with gear teeth '17 mesh- 'ing" with the rack 14. Awheel 18 is fixed to one end of the shaft and is provided with two pins19, by which the wheel and the shaft may be'turned. By turningthe shaftthe edges of the'body 13 may be moved apart "so as to increase thediameter of the body lugs 15. The gap in the mandrel is bridged andforce it outwardly against the work.

To hold the mandrel in expanded position the whe'el 18 is provided withratchet t'eeth 20,2which may be engaged by a pawl 21 pivoted on an arm22'integral with one of'the \Vitnesses by a curved plate 23 having afree sliding engagementpwith the extremities of the body 13.

' Various modifications may be made in the embodiment of my inventionhereinbefore described and illustrated in the accompanying drawings,within the nature of the invention and the scope of the followingclaims. a

Iclaim:

j 1. An'annular mold: for vulcanizing "tubes comprising a body portionhaving provision for heating it and-formed to nearly surroundthe'tubebut' provided with a gap for the insertion'or removal of thetube, the body portion having an inner vulcanizing surface to engage theouter surface of the tube, and a removable metal block inserted in saidgapand heated by conduction'froni the body portion, the block havingan'inner vulcanizing surface continuous with the inner surface of thebody portion.

2. Apparatus forvulcanizing' tubes 'comprising, in combination, a moldformed tonearly surround a tube but having a nan row gap, aremovable'metal block inserted in said gap and having'a surfacecontinuous withthe inner surface of the mold so. as to form an unbrokenvulcanizing surface to engage the'outer surface of the tube, and amandrel provided with means for ex anding it to force the tube outwardlyagainst the vulcanizing surface.

In testimony whereof I afiix my signature in presence of two witnesses.I

WILLIAM FROST.

H. HARVEY FRosT, H. D. JAMESON.

